Remove all frameworks except Bootstrap (#251)

- Remove all frameworks except Bootstrap

- Remove roots-options.php and replace with a more simple
  roots-config.php

- Include all Bootstrap Javascript plugins by default in
  js/plugins.js

- Use Bootstrap Responsive and Topbar navigation by default

- Use Bootstrap markup on forms, page titles, image galleries,
  alerts and errors, post and comment navigation

- Remove Roots styles from style.css and introduce app.css for
  site-specific CSS. Remove almost all previous default Roots
  styles.

- Add latest updates from H5BP project

css/less/accordion.less

@@ -0,0 +1,28 @@
+// ACCORDION
+// ---------
+
+
+// Parent container
+.accordion {
+  margin-bottom: @baseLineHeight;
+}
+
+// Group == heading + body
+.accordion-group {
+  margin-bottom: 2px;
+  border: 1px solid #e5e5e5;
+  .border-radius(4px);
+}
+.accordion-heading {
+  border-bottom: 0;
+}
+.accordion-heading .accordion-toggle {
+  display: block;
+  padding: 8px 15px;
+}
+
+// Inner needs the styles because you can't animate properly with any styles on the element
+.accordion-inner {
+  padding: 9px 15px;
+  border-top: 1px solid #e5e5e5;
+}